Endless belt for power transmitting

ABSTRACT

Endless belt for power transmitting according to the present invention is a tension-type belt by link chains, and has high power transmitting efficiency although it can be produced with relatively low cost. With this endless belt, the respective blocks and pins start to contact with sheave side in order near pitch line and the biting pitch into the sheave is made smaller so as to improve silence.  
     Even if the respective blocks  22, 23  are inclined at the time of biting of the endless belt into pulley, each block is contacted with the sheave side at only the projecting outer side face  45  formed in a predetermined bounds, corresponding to the divided pin near the pitch line (P-P). Therefore, total four parts, the projecting outer side faces  45, 45  of the first and second blocks, and a pair of the divided pins are abutted on the sheave side in order in one pitch of the link chain so as to make the biting pitch smaller and decrease polygon effects.

FIELD OF THE INVENTION

[0001] This invention relates to endless belt for power transmitting to be used for belt-type continuously variable transmission (CVT), especially to endless belt for power transmitting, connecting link plates by pins.

DESCRIPTION OF THE PRIOR ART

[0002] As this kind of endless belt for power transmitting, one which has been developed by Van Doorne's Transmissie (VDT) in the Netherlands (VDT; for instance, Japanese Patent No.1105154) has been used. The VDT belt is comprised by layered steel bands ceaselessly inserting metal V-shape blocks therebetween, and power is transmitted by contacting the side of the V-shape block and sheave faces of primary and secondary pulleys at lubricating environment, and by pushing the V-shape blocks each other.

[0003] In this VDT belt, biting pitch and polygon variation can be made smaller by making the V-shape block thinner, and the VDT belt is excellent in silence. But, the above-mentioned layered steel belt is made of high price material, and should be produced at high accuracy. Besides, in this steel belt, slip loss generates between layered steel belts in power transmitting state.

[0004] In the past, in order to solve the above-mentioned problems, the endless belt for power transmitting as shown in the Japanese patent application gazette (publication number H7-91498), for instance, has been proposed. As shown in FIG. 1, the metal belt is comprised of a plural number of first and second blocks 2, 3 located in a constant order in the longitudinal direction of a belt 1, a plural number of link plates 5 for connecting these blocks, pins 6 comprised of divided two pins (rocker pins) 6 a, 6 b for connecting these link plates, and spring means 7 stretching in the longitudinal direction of the link plate by engaging with these pins 6.

[0005] And, the endless belt for power transmitting has three open holes 9, 10, 9 formed on the first and second blocks 2, 3, and the link chain 11, alternately connecting the link plates 5 by the pins 6, penetrates these open holes 9, 10, 9. Since the pin 6 is engaged with the blocks 2, 3, the blocks 2, 3 and the link chain 11 are mutually connected with no end.

[0006] Besides, projection portions 2 a, 3 a are formed so as to abut backs of the first and the second blocks 2, 3 on each other, on the opposite sides, concave slots 2 b, 3 b for engaging with the pin are formed, and divided pins 6 a, 6 b are respectively engaged with these adjacent concave slots. On this occasion, in the first and second blocks 2, 3, the divided pins 6 a and 6 b are engaged with each other at their intermediate portions a, a and a predetermined clearance is formed at the both outer side portions b, b with respect to the divided pins. Then, the pins 6 a, 6 b are engaged with the pin engagement slots 2 b, 3 b formed on the intermediate portions a, a so as to support each block 2, 3 being free to oscillate with respect to the pins 6 a, 6 b.

[0007] Furthermore, both outer side faces of each block 2, 3 are inclined faces 2 c, 3 c so as to adjust on the sheave side face of each pulley. And, both outer side end faces of the pin 6 may be inclined face 6 c adjusting to the sheave side. The pin end face 6 c has R form on the face orthogonal to the longitudinal direction of the belt, such as A-A section, for instance, and can contact with the sheave face on a pitch circle of the belt.

[0008] In the present endless belt for power transmitting 1, torque is transmitted in such a manner that the torque of a pulley unit is transmitted from the sheave side face by contacting with the first and the second blocks 2, 3 and the pin 6, and tensile force acts on the link chain 11 comprising the link plates 5 through the pin 6.

[0009] In the above described metal endless belt 1, both side faces 2 c, 3 c of the first and the second blocks 2, 3 are formed in the shape of almost a straight line (they may be comprised of big arc, and they may be substantially contacted with the sheave side in a straight line by elastic deformation or the like) along the sheave side for almost its up and down. When the belt 1 is curved by biting into the pulley from the straight line state, then, both side faces of each block can start to contact with the sheave side at any position in its up and down direction. Then, the contact start position in the circumference direction (in the longitudinal direction of the belt) is changed by the position of the block in the radius direction for starting to abut.

[0010] For this reason, the blocks may start to contact with the sheave at their upper portion or lower portion by inclining the blocks 2, 3 with respect to the X-axis, the Y-axis or the Z-axis (as shown in FIG. 1, the longitudinal direction of the belt is X-axis, the right and left direction is Z-axis, and the up and down direction is Y-axis) or by bending the sheave at the time of biting in the pulley by the accuracy and deformation of the sheave side and the block. In this case, the contact start position of the blocks 2, 3 with the sheave in the circumference direction (in the longitudinal direction of the belt) overlaps the pin 6. That is, the contact of the blocks 2, 3 with the sheave and the contact of the pin 6 with the sheave simultaneously occur.

[0011] In order to decrease undesired noise at the time of biting into the pulley in the metal endless belt 1, it is preferable to make the biting pitch into the pulley (contact start position interval in the circumference direction) small as much as possible, and to decrease the angle between the belt contact positions adjacent to each other with respect to the pulley center, that is, polygon variation (polygon effects). But, when the contact start position of the block with the sheave overlaps the pin as mentioned before, the angle with the contact point adjacent to the contact point overlapping is made bigger, shifting the angle to be originally held between the block and the pin. Then, the biting pitch is made bigger to that extent, and undesired noise is increased.

[0012] On the other hand, if the shape of the end faces of the divided pins 6 a, 6 b is a flat face along the side of the sheave or is the R shape with respect to the face orthogonal (radius direction) to the longitudinal direction of the belt as the prior art above-mentioned (The R shape in the direction is the shape along the side of the sheave on the pitch circle, and is substantially the same as the above-mentioned flat face concerning the rotation of the pin at the time of biting), the substantial width of the pin (the relative clearance between the pin and the sheave) is widely changed by the spin (rotation) of the pin when the belt is bitten into the pulley and the blocks and the divided pins are rotated, fitting the effective diameter of the pulley. Then, the contact position between the pin and the sheave (in the circumference direction and radius direction) is changed (change of the position where the pin starts to bite), and the above-mentioned polygon effects are actualized so as to cause undesired noise. At the same time, slip of the pin with respect to the sheave, especially the slip in the radius direction is made bigger.

[0013] Furthermore, by contacting the pin with the sheave at the position away from the rotational center of the pin, spin loss increases with the spin (rotation) of the pin. Besides, power loss generates by the change of the relative clearance between the pin and the sheave, especially by the slip in the radius direction so as to reduce the power transmitting efficiency.

[0014] Then, the first object of the present invention is to provide endless belt for power transmitting which is a tension-type belt using a link chain, having high power transmitting effects although it can be produced with relatively low cost, and having such a structure that the respective blocks and pins start to contact with the sheave side in order near the pitch line and the biting pitch into the sheave is made smaller so as to improve silence.

[0015] The second object of the present invention is to provide endless belt for power transmitting, reducing the variation of the substantial pin width in spite of the rotation of the pin when the endless belt is bitten into the pulley so as to reduce undesired noise by the polygon effects and power loss by the spin loss of the pin.

SUMMARY OF THE INVENTION

[0016] The present invention according to claim 1 (see FIG. 2 through FIG. 7, for instance) is endless belt for power transmitting having many pins comprising a pair of divided pins having rolling surfaces capable of abutting on each other, many link plates comprising link chains alternately connected by said pins, and first and second blocks having projection portions capable of contacting with each other in front and rear direction, a concave slot provided on the opposite side for receiving said divided pin, and an open hole penetrating said link chain in said front and rear direction, comprising:

[0017] said divided pins having shape and length such that both outer side ends in its right and left can be contacted with sheave sides of a pulley; and

[0018] said first and second blocks having projecting outer side faces at positions almost corresponding to said outer side end faces of said divided pins in both outer side faces of their right and left, projecting in the right and left direction and having a shape capable of contacting with said sheave sides of said pulley, and

[0019] said endless belt for power transmitting having such a structure that total four parts, a pair of said divided pins, said projecting outer side faces of said first and second blocks, are contacted with said sheave side in order in one pitch of said link chain.

[0020] According to the present invention concerning claim 1, the contact bounds of the block with the sheave side is limited to predetermined bounds near the pitch line in order to correspond to the pin. Even if the sheave is bent or the block is inclined, then, total four parts, a pair of divided pins and the projecting outer side faces of the first and second blocks are contacted with the sheave with respect to one pitch of the link chain so as to make the biting pitch smaller and to decrease polygon effects. Therefore, in the endless belt for power transmitting, undesired noise can be decreased so as to improve silence although it is a tension-type one comprising the link chains and blocks, and has high power transmitting efficiency, and can be produced with relatively low cost.

[0021] Besides, even if the blocks are inclined with respect to the front and rear direction (in the longitudinal direction of the belt; the Z-axis), the variation of the block width by the inclination in the front and rear direction is small, the load on the sheave is small, and the influence on the durability of the pulley and the block is few since the contact bounds of the block with the sheave side are restricted.

[0022] According to the present invention of claim 2 (see FIG. 7, for instance) is the endless belt for power transmitting as set forth in claim 1, wherein said projecting outer side faces in said first and second blocks are formed in the shape of almost straight line, having a predetermined inclined angle (they may have big arc, and include the case where they are substantially contacted with the sheave side by elastic deformation or the like) so as to match with the sheave side, and are near pitch line, and are shorter than length in up and down direction of said concave slot.

[0023] According to the invention of claim 2, the projecting outer side face of the block is in the shape of almost a straight line having a predetermined inclined angle, and the contact area with the sheave side can be secured. In spite of this, the biting position of the block with respect to the pin can be correctly maintained at the time of biting into the sheave side.

[0024] The present invention of claim 3 (as shown in FIG. 9 (B), for instance) is the endless belt for power transmitting as set forth in claim 1, wherein said first and second blocks have said concave slots holding and contacting with said divided pins on both side portions of their right and left, and said open hole is formed between said both side portions.

[0025] According to the present invention of claim 3, the concave slots for holding the pin and the projection portions contacting with each other are formed at both side portions of right and left of the block. Then, the length of the concave slot and the projection in the right and left direction is secured so as to improve load stress of the block. Besides, the relatively long open hole is secured between both side portions, and the number of the link plates of the link chain penetrating in the open hole is secured so as to improve torque capacity and durability.

[0026] The present invention of claim 4 (as shown in FIG. 3, for instance) is the endless belt for power transmitting as set forth in claim 1, wherein said divided pin is located in said slot in order to operate such that moment with contact between said concave slot and said divided pin denies moment acting on said first and second blocks since these blocks contact with said sheave side at said projecting outer side face positioning on said projection portion.

[0027] According to the present invention of claim 4, the moment acting on each block in the state of contacting with the pulley is denied, making use of the moment by the contact between the pin and the concave slot so as to restrict the change of position of each block.

[0028] The present invention of claim 5 is the endless belt for power transmitting as set forth in claim 4, wherein abutting position between said divided pin and said concave slot is located at a position shifted in outside diameter direction with respect to pitch circle of said belt.

[0029] According to the present invention of claim 5, the abutting position between the divided pin and the concave slot are located at the position shifting in the outside diameter direction from the pitch circle of the belt so as to easily generate the moment in the direction opposite to the moment acting between the block and the pulley.

[0030] The present invention of claim 6 is the endless belt for power transmitting as set forth in claim 1, wherein said outer side end face of said divided pin is formed, curved in the longitudinal direction of said belt.

[0031] According to the present invention of claim 6, the outer side end face of the divided pin is formed, curving in the longitudinal direction of the belt so as to contact the outer side end face of the divided pin and the sheave side with each other near the apical portion of the curved portion. Then, it can be prevented that the top end side in the belt running direction of the outer side end face of the divided pin firstly contacts with the sheave side so as to make the biting pitch bigger. So silence is improved.

[0032] The present invention of claim 7 is the endless belt for power transmitting as set forth in claim 3, wherein only one of said open hole is formed between said concave slots.

[0033] According to the present invention of claim 7, the production and assembly can be made easier by forming only one open hole.

[0034] The present invention of claim 8 is the endless belt for power transmitting as set forth in claim 7, wherein a guide face is respectively formed on said open hole side of said concave slots, and said guide face and said link plate on utmost outer side of said link chain are abutted on each other.

[0035] According to the present invention of claim 8, the width of the link chain can be correctly provided by the guide face. Besides, the block can be smoothly oscillated by guiding with the link plate, so silence is improved.

[0036] The present invention of claim 9 is the endless belt for power transmitting as set forth in claim 1, wherein a stopper for restricting relative rotation quantity of said divided pin is provided with upper and lower of said concave slot.

[0037] According to the present invention of claim 9, the block can be held with respect to the pin in the predetermined bounds so as to oscillate, and occurrence of the interference among the blocks can be provided.

[0038] The present invention of claim 10 is the endless belt for power transmitting as set forth in claim 1, wherein said outer side end face of said divided pin is formed in the shape of a straight line having a predetermined inclined angle, seen from said longitudinal direction of said belt.

[0039] According to the present invention of claim 10, the outer side end face of the divided pin and the sheave side can be smoothly contacted with each other.

[0040] The present invention of claim 11 (see FIG. 2 through FIG. 8, FIG. 9 and FIG. 10, for instance) is the endless belt for power transmitting having many pins each having a rolling surface and many link plates alternately connected by said pins so as to comprise a link chain, comprising:

[0041] said pin having shape and length wherein its both right and left outer side faces can contact with sides of sheaves of a pulley; and

[0042] said end face of said pin having curved shape in at least X direction with a longitudinal direction of said endless belt as said X direction.

[0043] According to the present invention of claim 11, since the shape of the end face of the pin has curved shape at least in X direction, the variation of the pin width by the rotation of the pin when the pin is bitten into the pulley can be made smaller in comparison with the pin which end face shape is flat face or curved shape in Y direction. And, the polygon effects can be decreased to that extent. At the same time, the deformations of the pin and the sheave in width direction are decreased so as to improve its durability, and the slip between the pin and the sheave, especially the slip in the radius direction and the rotational (spin loss) direction is decreased so as to decrease power loss and so as to improve power transmitting efficiency.

[0044] The present invention of claim 12 (see FIG. 8 and FIG. 10, for instance) is the endless belt for power transmitting as set forth in claim 11, wherein said shape of said end face of said pin is almost cylindrical one having curved shape in said X direction.

[0045] According to the present invention of claim 12, since the above-mentioned curved shape is made almost cylindrical shape, two-dimensional grinding machining is sufficient to produce the pin end face, and its manufacture can be made simple in comparison with case where the shape of the pin end face is machined into a spherical shape and its machining efficiency can be improved. Furthermore, the influence on the substantial width of the pin by the change of the curved shape in X direction is widely big in comparison with one by the change in Y direction. Even if the pin end face is made cylindrical shape which changes in X direction only, there is no big influence on the noise of the belt by actual use and the power efficiency. Besides, by making the belt end face cylindrical, Hertz stress is made smaller in comparison with spherical shape, and it is possible to hold the strength of the endless belt enough to secure the predetermined torque capacity by pressing the endless belt to the side of the sheave of the pulley.

[0046] The present invention of claim 13 is the endless belt for power transmitting as set forth in claim 11, wherein said pin is comprised of a pair of divided pins having rolling surfaces capable of abutting on each other.

[0047] According to the present invention of claim 13, since the pin is the divided pins having rolling surfaces abutting on each other, it has sufficient strength and can be made high credible structure by certainly rolling so as to decrease power loss.

[0048] The present invention of claim 14 is the endless belt for power transmitting as set forth in claim 11, wherein said curved shape is R shape which radius (Rp) is in the bounds of 5-15 [mm].

[0049] According to the present invention of claim 14, by making the curved shape the R shape which radius is the bounds of 5-15 [mm], the strength concerning the above-mentioned Hertz stress can be maintained, and the variation of the width by the pin rotation can be restricted within the bounds capable of permitting on belt efficiency.

[0050] The present invention of claim 15 (see FIG. 17 through FIG. 29, especially FIG. 28, for instance) is the endless belt for power transmitting as set forth in claim 14, wherein the shape of said end face of said divided pin has discrepancy (a, aA) of the center of radius (Rp) of said R shape with respect to the rotational center (O) of said pin in said X direction obtained in such a manner that variation (ε) of pin width obtained from a clearance (δ) between said pin end face and said sheave in said X direction is equally distributed to positive rotational side and negative rotational side of rotational angle (θ) in variation (η a) of the rotational angle within the bounds to be used by said pin.

[0051] According to the present invention of claim 15, the discrepancy of the center of the radius of the R shape with respect to the rotational center of the pin in X direction is determined in such a manner that the variation of the pin width is equally distributed on its positive rotational side and its negative rotational side in the variation of the rotational angle in the bounds to be used by the pin (is not always divided in a positive value or a negative value, and may be both positive value or both negative value on both rotational sides). Then, the shape of the pin end face can be set so as to make the variation of the pin width the smallest, and highly efficient endless belt, decreasing noise and power loss can be obtained.

[0052] The present invention of claim 16 is the endless belt for power transmitting as set forth in claim 15, wherein said discrepancy is within the bounds from −0.2 to +0.2 [mm].

[0053] According to the present invention of claim 16, since the above-mentioned discrepancy is in the bounds from −0.2 to +0.2 [mm], the variation of the pin width can be restricted in the bounds having no big influence in the attaching angle of the link plate of the divided pin, and the endless belt having efficiency with no hindrance on practical use can be provided.

[0054] The present invention of claim 17 is the endless belt for power transmitting as set forth in claim 16, wherein said discrepancy is a value which does not include 0.

[0055] According to the present invention of claim 17, when the discrepancy of the center of the radius (X coordinates) of the R shape of the pin end face with respect to the rotational center of the pin is 0, the variation of the pin width in the bounds of the change of the rotational angle of the pin is the maximum in the rotational angle of the pin (the same as the attaching angle of the link plate of the pin) in the position where the belt starts to bite into the pulley, and is smaller in the rotational angle of the pin where the belt is rotated and the rotation of the pin finishes in the divided pin of the front side in the moving direction of the belt. In the result, the variation of the pin width is made bigger in the bounds of the change of the rotational angle of the pin. When the discrepancy does not include 0, that is, when the rotational center of the pin and the center of the radius (X coordinates) of the R shape of the pin end face are not corresponded with each other (the shifted direction is on the positive side (the right direction) and on the negative side (the left direction) with respect to Y axis for the center of the radius of the pulley by the attaching angle of the link plate of the pin), the variation of the pin width can be restricted to the smaller value in the bounds of the change of the rotational angle of the pin.

[0056] The present invention of claim 18 (see FIG. 3, FIG. 28, FIG. 29, for instance) is the endless belt for power transmitting as set forth in claim 15, wherein said a pair of divided pins are attached to said link plate so as to sit on a sheet hole formed on said link plate on the side opposite to said rolling surface, and said divided pin of front side of moving direction of said endless belt in a pair of divided pins is attached to said link plate with a predetermined value (f; 5°, for instance) of positive rotational direction with respect to Y direction orthogonal to said X direction with the rotation in the moving direction of said endless belt as its positive rotation.

[0057] According to the present invention of claim 18, the divided pin of the front side of the moving direction of the belt is attached to the link plate with the predetermined value of the positive rotational direction. Then, when the endless belt is bitten into the pulley, the divided pin is rotated in the negative rotational direction from the predetermined value of the positive rotational direction when the belt is in the state of almost a straight line, and becomes to be the predetermined value of the negative rotational direction at the time of finishing biting into the pulley. On this occasion, the rolling surface of the divided pin can be used on both sides holding the center line, it is advantageous on strength. Besides, the variation of the pin width can be restricted to small value with the setting of the predetermined discrepancy.

[0058] The present invention of claim 19 (see FIG. 28, for instance) is the endless belt for power transmitting as set forth in claim 18, wherein the center of radius (Rp) of said R shape of said divided pin of said front side has a predetermined discrepancy (aA) on rear side of said moving direction of said endless belt with respect to said rotational center (O) of said pin.

[0059] According to the present invention of claim 19, the predetermined discrepancy of the divided pin on the front side is shifted on the rear side of the moving direction of the belt (on the positive side) Then, the variation of the pin width can be restricted to small value with the attaching angle of the link plate of the divided pin.

[0060] The present invention of claim 20 is the endless belt for power transmitting as set forth in claim 19, wherein said radius of said R shape is almost 10 [mm], and said predetermined discrepancy (ah) is almost 0.03 [mm].

[0061] According to the present invention of claim 20, an optimum shape of the pin end face can be provided in such a manner that if the radius of the R shape of the pin end face is almost 10 [mm], and the predetermined discrepancy is almost 0.03 [mm],the practical endless belt which effective diameter of the pulley is about 28 [mm] in the minimum diameter, and is about 69 [mm] in the maximum diameter is adopted to make the variation of the pin width the smallest.

[0062] The present invention of claim 21 (see FIG. 2 through FIG. 8, for instance) is the endless belt for power transmitting as set forth in claim 13, wherein at least one block having an open hole being penetrated by said link chain in said X direction held between said pins adjacent to each other in said X direction, is provided, said block projects in right and left direction at a position almost corresponding to said outer end face of said pin in both right and left outer side faces, and has projecting outer side faces comprised of the shape capable of contacting with said sheave sides (V) of said pulley.

[0063] According to the present invention of claim 21, the projecting outer side face is provided with the block such that the contacting bounds with the sheave side is restricted to the predetermined bounds near the pitch line so as to correspond to the pin. Then, the block and the pin can be certainly contacted with the sheave side with the shape of the pin end face.

[0064] The present invention of claim 22 (see FIG. 2 through FIG. 8, for instance) is the endless belt for power transmitting as set forth in claim 21, wherein said block is comprised of first and second blocks, having a projection portion capable of contacting with each other in said X direction and a concave slot for receiving said divided pin on the opposite side, and total four parts, said outer end faces of a pair of said divided pins, said projecting outer side faces of said first and second blocks, are contacted with said sheave side in order in one pitch of said link chain.

[0065] According to the present invention of claim 22, the total four parts, the outer side ends of a pair of the divided pins and the projecting outer side faces of the first and the second blocks are certainly contacted with the sheave side with respect to one pitch of the link chain in a predetermined time series. Then, the biting pitch is made smaller, and polygon effects are decreased. Therefore, the endless belt having superior efficiency, decreasing noise and improving durability, can be provided although this is the tension-type endless belt, and power transmitting efficiency is high and it can be manufactured with relatively low cost.

[0066] On the basis of the above-mentioned structure, even if the sheave is bent or the respective blocks (22), (23) are inclined with respect to the X-axis, the Y-axis, and the Z-axis at the time of biting of the endless belt (21) into the pulley, each block contacts with the sheave side on only the projecting outer side end (45) formed in the predetermined bounds near the pitch line (P-P) , corresponding to the divided pin (26 a) (26 b). Then, the projecting outer side face (45) of the first block (22), one divided pin (26 b) , the other divided pin (26 a) and the projecting outer side face (45) of the second block (23) are abutted on the sheave side in order in one pitch of the link chain (32) so as to make the biting pitch smaller and to decrease polygon effects.

[0067] On the contrary, the conventional blocks (2), (3) contact with the sheave side, by almost whole length of the outer side faces (2 c), (3 c) stretching in the up and down direction. Then, the contacting thickness (t) of the block in the front and rear direction including the projection portions (2 a), (3 a) is thick. In case where the respective blocks (2), (3) are inclined (that is, with respect to the Z-axis) in the front and rear direction (in the longitudinal direction X of the belt) as shown in FIG. 10 (a), for instance, the thick contacting thickness (t) influences the variation A of the block width as it is such that the variation becomes to be bigger.

[0068] With the above-mentioned structure of the present invention, the part of the block (22), (23) contacting the sheave side is only the projecting outer side face (45) having the predetermined bounds near the pitch line. Then, as shown in FIG. 10 (b), for instance, even if the block is inclined in the front and rear direction (with respect to the Z-axis), its influence acts on only the projection portion (41) on which the projecting outer side face (45) positions. So, the variation (C) of the block width (B) is widely smaller than the conventional one.

[0069] On the other hand, the pins, such as the divided pins (26 a, 26 b) are rotated, fitting the curve of the link with the biting of the endless belt (21) into the pulley. The end faces (26 c) of both right and left sides of the pin have the shape wherein the variation (ε) of the pin width (B) is small by the rotation of the pin. The biting pitch of the pin end face into the sheave is maintained constant, the polygon effects are maintained small, occurrence of noise is decreased, the influence on the sheave by the rotational angle of the pin and the influence on the block is decreased so as to improve the durability of the belt-type continuously variable transmission. Besides, the power transmitting efficiency can be improved with the reduction of the spin loss of the pin.

[0070] On this occasion, the numerals and the marks in parenthesis are for contrasting with drawings. But, these numbers and marks are used for convenience, corresponding to the forms of the embodiments, in order to easily and speedily understand the present invention, and no influence is given to the descriptions of claims by the numerals and the marks.

BRIEF DESCRIPTION OF THE DRAWINGS

[0071]FIG. 1 is a view showing a conventional endless belt for power transmitting, (a) is a side view including sections in part (B-B section and C-C section of (b) and (b) is a A-A sectional view of (a);

[0072]FIG. 2 is a side view showing the endless belt for power transmitting according to the present invention;

[0073]FIG. 3 is an enlarged side view showing the portion gearing the endless belt for power transmitting into a pulley;

[0074]FIG. 4 is a front sectional view of FIG. 3;

[0075]FIG. 5 is a plan view of FIG. 3;

[0076]FIG. 6 is a view for showing parts of the endless belt for power transmitting according to the present invention, (a) and (b) show a block, (c) shows a link plate, and (d), (e) show spring means;

[0077]FIG. 7 is a enlarged view showing the block, (a) is a A-A sectional view in (b), and (b) is a front view showing a part;

[0078]FIG. 8 is an enlarged view showing a divided pin, (a) is a side view, (b) is a front view and (c) is a C-C sectional view of (b);

[0079]FIG. 9 is a view comparing the one of present invention (shown with full line) and the conventional one (shown with dashed line), (A) shows the link plate, (B) shows block, (C) shows the pin, (a) is a front view, and (b) is a side view;

[0080]FIG. 10 is a plan view showing the block inclined in the front and rear direction, (a) relates to the conventional one, and (b) relates to the one of the present invention;

[0081]FIG. 11 is a side view of end face of pin for analyzing change of clearance between the pin and sheave by rotation of the pin;

[0082]FIG. 12 is a sectional view of the end face of the pin in X direction (in circumference direction), typically enlarged its scale;

[0083]FIG. 13 is a sectional view of the end face of the pin in Y direction (in radius direction), typically enlarged its scale;

[0084]FIG. 14 (a) shows Y direction (radius direction) and FIG. 14 (b) shows X direction (circumference direction) when R shape of the end face of the pin is inclined on X and Y coordinates;

[0085]FIG. 15 is a view showing clearance between the pin and the sheave in Y direction with the pin rotational angle as its parameter when the shape of the end face of the pin is flat and effective diameter of pulley is the minimum diameter;

[0086]FIG. 16 is a view the same as FIG. 15 when the shape of the end face of the pin is flat and effective diameter of pulley is the maximum diameter;

[0087]FIG. 17 is a view showing clearance between the pin and the sheave in X direction with the pin rotational angle as its parameter when the shape of the end face of the pin is flat and effective diameter of pulley is the minimum diameter;

[0088]FIG. 18 is a view the same as FIG. 17 when the shape of the end face of the pin is flat and effective diameter of pulley is the maximum diameter;

[0089]FIG. 19 is a view showing clearance between the pin and the sheave in X direction with the pin rotational angle as its parameter when the shape of the end face of the pin is R shape, center of the R shape and rotational center of pin are corresponded with on X axis, and the effective diameter of pulley is the minimum at y₀=0;

[0090]FIG. 20 is a view showing values on X-axis, shifted 1.5 [mm] on the upper hand in Y direction;

[0091]FIG. 21 is a view showing values on X-axis, shifted 1.5 [mm] on the lower hand in Y direction;

[0092]FIG. 22 is the same view when the center of R shape of the end face of the pin is shifted predetermined quantity in right direction (in the positive direction) on X axis with respect to the rotational center of the pin and the pulley effective diameter is the minimum diameter;

[0093]FIG. 23 is the same view when the center of R shape of the end face of the pin is shifted predetermined quantity in left direction (in the negative direction) on X axis with respect to the rotational center of the pin and the effective diameter of the pulley is the minimum diameter;

[0094]FIG. 24 is a view similar to FIG. 19 when the effective diameter of pulley is the maximum diameter;

[0095]FIG. 25 is a view similar to FIG. 22 when the effective diameter of pulley is the maximum diameter;

[0096]FIG. 26 is a view similar to FIG. 23 when the effective diameter of pulley is the maximum diameter;

[0097]FIG. 27 is a typical view showing the state that the endless belt bites into pulley;

[0098]FIG. 28 is a view showing relation between the effective diameter of pulley and variation of rotational angle with link pitch as a parameter;

[0099]FIG. 29 is a view showing change of clearance with sheave by the rotation of the pin with the rotational angle of the pin as a parameter, for explaining for obtaining variation of the pin width;

[0100]FIG. 30 is a view showing variation of the pin width by the pin rotational angle as discrepancy a of the center of R shape of the end face of the pin as a parameter when the effective diameter of pulley is the minimum diameter;

[0101]FIG. 31 is a view similar to FIG. 30 when the effective diameter of pulley is the maximum diameter;

[0102]FIG. 32 is a view showing biting position by the pin rotational angle with the discrepancy of the center of R shape of the end face of the pin as a parameter when the effective diameter of pulley is the minimum diameter; and

[0103]FIG. 33 is a view similar to FIG. 32 when the effective diameter of pulley is the maximum diameter.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0104] Embodiments of the present invention will now be explained with accompanying drawings hereinafter. FIG. 2 is a side view showing an endless belt for power transmitting made of metal which relates to the present invention. FIG. 3 is an enlarged side view showing biting portion into pulley of the endless belt for power transmitting. FIG. 4 is a front sectional view. FIG. 5 is a plan view.

[0105] An endless belt for power transmitting 21 has a plural number of first and second blocks 22, 23 located in a constant order in the longitudinal direction, a plural number of link plates 25 and pins 26 for connecting these blocks, and spring means 27 stretching in the longitudinal direction of the link plate 25 by engaging with these pins, similar to the belt 1.

[0106] The link plate 25 is a steal plate produced by fine blanking or the like, having a predetermined shape, as shown in FIG. 3 and FIG. 6 (c) in detail. At both end portions, a pin hole 30, comprised of holes 30 a, 30 b for receiving a pair of divided pins 26 a, 26 b is formed respectively. The pin 26 is comprised of a pair of divided pins (rocker pins, sheet pins) 26 a, 26 b symmetrical in mirror which opposing faces are rolling surfaces 31 a, and is unitedly engaged with the link plate by contacting a side face 31 b opposed to the rolling surface with the sheet hole 30 a outside the link plate 25. And, a link chain 32 is comprised by alternately connecting the respective link plates 25 by the pin 26.

[0107] And, as shown in FIGs. 2, 4, 5 and 6 (d) and (e), the spring means 27, having C shape when it is seen from the side face, is provided extending between both pins 26 so as to shrink with the central portion in rank G which is one line in the lateral direction of the link chain 32. The spring means 27 is provided with each rank G every other one, its shrinkage force is acted on each pin 26, frictional force is added between the block and the link plate contacting each pin. The pin can be provided from shifting in the axial direction and dropping out by the frictional force, especially in the belt assembly state and in the belt loosening state.

[0108] As shown in FIG. 3 and FIG. 5, one divided pin 26 a sits on the sheet hole 30 a of the link plate 25 of a predetermined rank G₁ of one line of the lateral direction of the link chain so as not to rotate, and the other divided pin 26 b is inserted into the other hole 30 b, having a space in the hole. And, the other divided pin 26 b sits on the sheet hole 30 a of the link plate 25 of the rank G₂ adjacent to the rank G₁ so as not to rotate. By contacting the rolling surfaces 31 a of both pins 26 a, 26 b with each other so as to roll, the ranks G₁ and G₂ can be bent. By doing so, the endless belt 21 is wound around, corresponding to the effective diameter of the pulley set by a pair of sheave interval, and speed is changed with no step by the speed change activity of the pulley (change of effective diameter) so as to transmit power.

[0109] On the other hand, the pin 26 extends, projecting in the right and left direction of the rank G . . . , and abuts on the first and the second blocks 22, 23, as shown in FIGs. 4 and 5. The first and the second blocks are symmetrical in mirror. The first block will now be explained hereinafter. The second block 23 is similar to the first block. As shown in FIGS. 4 and 6, the block 22 (23) has an open hole 35 having almost rectangle shape in its central portion, and has an upper side portion 36, a lower side portion 37 and right and left side portions 39, 39 at its periphery. The link chain 32 is located in the open hole 35 so as to penetrate, and the block 22 is abutted on the pin 26 at the right and left side portions 39, 39.

[0110] As shown in FIG. 7 in detail, the block 22 (23) has a concave slot 40 formed on a side face of the front or rear direction in its right and left side portions 39, and has a projection portion 41 formed on its opposed face, and the wall thickness of the block is almost the same in radius direction. One of the divided pins 26 a, 26 b is received in the concave slot 40, and the concave slot 40 abuts on the pin near the center position in the radius direction in the opposite side 31 b of the pin. And, the upper and lower faces of the concave slot are formed in an arc shape having a space so as to permit relative rotation between the block and the pin. Furthermore, projections 42 a, 42 b, projecting in the front and rear direction (in the longitudinal direction of the belt) are formed so as to hold the pins 26 a, 26 b on the upper and lower faces of the concave slot 40. By the engagement between the projection and the pin, the relative rotational quantity of the block 22 (23) with respect to the pin is restricted. Then, the projecting quantity j of the block 22 (23) is small formed within the bounds of maintaining the minimum winding angle on the pulley.

[0111] As shown in FIG. 7 (b) in detail, an outer side face 45 of the concave slot 40 portion in the block 22 (23) is formed, projecting a predetermined quantity in the right and left direction (in the axial direction of the pin). The projecting outer side face 45 has inclined angle β almost the same as one of the sheave side V, and only projecting outer side face 45 can be contacted with the sheave side in the block outer side portion 39. The projecting outer side face 45 is on the position almost corresponding to one of an outer side end 26 c of the divided pins 26 a, 26 b. And, the projecting outer side face 45 has almost straight line shape (may be comprised of a big arc substantially contacting with the sheave side by elastic deformation or the like) of the predetermined inclined angle β in the up and down direction (in the radius direction) so as to match with the sheave side V, and has almost straight line in the front and rear direction also (in the longitudinal direction of the belt), that is, has almost flat shape of the predetermined area. The projecting outer side face 45 is on the position almost corresponding to the pin 26 in the longitudinal direction of the belt, and in more detail, is near the pitch line P-P of the belt, and it's width in the radius direction is length 1 slightly shorter than length L in the radius direction of the concave slot 40.

[0112] Besides, faces 46 a, 46 b are formed in the up and down direction of the concave slot 40 on the open hole 35 side of the block outer side portion 39. These faces 46 a, 46 b provide the width W1 of the link chain 32, as shown in FIG. 4, and abut on the utmost outer link plate 25 so as to smoothly guide the oscillation of the blocks 22, 23 with respect to the link plate 25.

[0113] On the other hand, as shown in FIG. 4, the divided pin 26 (only one divided pin 26 a is explained, but the other divided pin 26 b is similar since both are symmetrical in mirror) has almost the same dimension as the projecting outer side faces 45 of the block in the right and left (width) direction. Both outer side ends 26 c, 26 c of the divided pin 26 a have almost the same inclined angle β as one of the sheave face, similar to the projecting outer side face 45, and both outer side ends 26 c of the pin contact with the sheave side face with both projecting outer side faces 45 of the block. The pin outer side end 26 c is located so as to almost correspond to the projecting outer side face 45 of the block in the longitudinal direction of the belt, and length m in the radius direction is almost the same as the length l of the block projecting outer side face 45 or is slightly bigger than the length l.

[0114] As shown in FIG. 8 (a) in detail, the divided pin 26 a (26 b) is comprised of the rolling surface 31 a which is curved face having big curvature, and the sheet face 31 b on the opposite side which is curved face of the combination of the arcs sit on the link plate sheet hole 30 a. And, as shown in FIG. 8 (b), the outer side end 26 c is the straight line having the predetermined inclined angle excluding the upper and the lower R portions, seen from the front face (seen from the longitudinal direction of the belt). As shown in (c) which is the C-C section of FIG. 8 (b) , the pin outer side end 26 c is comprised of the curved face R, such as arc or the like having the predetermined radius, seen from the plane (seen from the outside in the radius direction). The utmost apical portion s of the curved face R is on the position shifted the predetermined quantity on the rolling surface 31 a side with respect to the center line CL (X axis) in the front and rear direction of the pin. Then, the pin outer side end 26 c is designed so as to contact with the sheave side for the length m in the radius direction at the utmost apical portion s portion of the curved face R shifted on the rolling surface side. The end face 26 c of the pin 26 is a straight line, seen from the front face (Y direction) (see FIG. 8 (b)) since it is easy on machining. But, in a similar way to a conventional pin, it may be R (curved) shape, seen from the front face. And, the length in the right and left direction (width direction) of the pin 26 a (26 b) in the pitch line P-P is set so as to be almost the same as that of the block 22 (23). In one pitch of the link chain 32 (that is, the length of one sheet of the link plate), the end faces 26 c, 26 c of the two divided pins 26 a, 26 b and the projecting outer side faces 45, 45 of two blocks 22, 23, that is, total four are located at almost equal intervals. These four, the end faces 26 c, 26 c and the projecting outer side faces 45, 45 can all contact with the sheave side. Besides, the curved shape of the pin end face is preferably an arc face (R shape) having a predetermined center. But, exactly speaking, the shape having rounding, such as ellipse and another curved surface, is also sufficient besides true circular shape.

[0115]FIG. 9 is the drawing showing comparison between the present invention (full line) and the prior art (see FIG. 1) (dashed line) concerning the link plate (A) , the block (B) and the pin (C). A conventional link plate (5) is in the shape of a ring, and right and left pin holes communicate with each other. But, the link plate (25) of the present invention has the hole 30 which is comprised of sheet hole 30 a and the hole having a space 30 b on its right and left. The conventional blocks 2, 3 separately support the link chain, by the three open holes 9, 10, 9. On the other hand, the blocks 22, 23 of the present invention collectively support one link chain 32 by one open hole 31 although the total number of the link plates is the same as one of the conventional link plates. Furthermore, the conventional block supports the pin 6 at the intermediate portions a, a, and has a space between it and the pin at both outer side portions b, b. Load from the blocks 2, 3 is transmitted to the pin by the pin slots 2 b, 3 b, and each pin end face 6 c and both sides 2 c, 3 c of the blocks 2, 3 are abutted on the sheave side in spite of slight dimensional error of the pin or the block, permitting the deformation of the pin and the block. On the other hand, the blocks 22, 23 of the present invention are abutted on and supported by the pin 26 in the concave slot 40 of the both right and left side portions 39, and the length Q in the axial direction (in the right and left direction) of the abutting portion is longer than the length U of one of the prior art(Q>U). Then, the contact area between the block and the pin and between the projection portions 41 of the blocks is made bigger, and power transmitting by the contact pressure between the block and the pin and between the blocks is advantageous. Besides, the block (and the pin) has high rigid structure with respect to the holding pressure from the sheave.

[0116] And, in the prior art, dent c for pin interference prevention is provided at the lower portion of the concave slot, and the block escapes from the pin so as to oscillate mainly on the lower hand. On the other hand, in the present invention, the concave slots 40 are almost symmetrical with respect to the pitch line, seen from the side (see FIG. 9 (b)), and the pin and the block almost abut on each other with the pitch line as its center. Then, the block escapes from the pin so as to oscillate the upper and the lower hands. And, with the outer end face 6 c of the conventional pin 6, the R form r, seen from the side, that is, on the face parallel to the paper of FIG. 9 (C), is formed. On the other hand, the R form R, seen from the plane, on the face parallel to the face perpendicular to the paper of FIG. 9 (C), (see FIG. 8 (c)), is formed on the pin 26 of the present invention, and the formed plane of R form is different 90 degree. Besides, the length L1 (see FIG. 8 (c)) in the front and rear direction (in the longitudinal direction of the belt) on the pitch line is almost the same as the length L 2 (see FIG. 7 (a)) of the projecting outer side faces 45 of the blocks 22, 23.

[0117] Furthermore, the shape of the outer end face 26 c of the divided pins 26 a, 26 b (only “pin 26” hereinafter) will now be explained according to FIG. 11 through FIG. 33 in detail. The width B (the length in the pin axis direction; see FIG. 4) of the pin 26 contacting the right and left outer side ends 26 c of the pin with the sheave when the endless belt 21 bites into the pulley is determined by the minimum value of the clearance between the end face of the pin and the sheave. When the pin is rotated, the clearance between the end face of the pin and the sheave is changed so as to change the substantial pin width. That is, the belt 21 being in a straight line state at the time of biting into the pulley is curved (bent) along the effective diameter of the pulley. On this occasion, the pin 26 is rotated, and the abutting position (the substantial pin width) of the end face of the pin is determined on the basis of the clearance between the end face of the pin and the sheave.

[0118] As shown in FIG. 11, the center O of the rotation of the divided pins 26 a, 26 b rotating on the rolling surfaces 31 a with each other is on the intersection between the line for the center of the pulley of the pin 26 (Y axis) and the line along the longitudinal direction of the belt in the half of the length m in the radius direction of the pin on the Y axis (in the circumference direction) (X axis). When the pin is rotated θ degree with the rotational center O, an usual equation for obtaining the value of the clearance δ (both sides) with the sheave in an optional point A is as follows. $\begin{matrix} {{\left. {\delta = {{{2\left\{ \sqrt{\left\{ {x_{1}^{2} + \left( {R_{0} + y_{1}} \right)^{2}} \right\} - \left( {R_{0} + y_{0}} \right)} \right\} \times \tan \quad \beta} + c} = {{2\left\{ {\sqrt{\left\{ {\left( {x_{0}^{2} + y_{0}^{2}} \right)\sin^{2}\left\{ {{\pm^{*3}\theta} \pm^{*1}{\tan^{- 1}\left( {x_{0}/y_{0}} \right)}} \right\}} \right.} + \left\{ {R_{0} \pm^{*2}{\sqrt{{\left( {x_{0}^{2} + y_{0}^{2}} \right)\cos}\quad}\left\{ {{\pm^{*3}\theta} \pm {\tan^{- 1}\left( {x_{0}/y_{0}} \right)}} \right\}}} \right\}^{2}} \right\}} - \left( {R_{0} + y_{0}} \right)}}} \right\} \times \tan \quad \beta}\quad + c} & (1) \end{matrix}$

x ₁ =r sin (θ+α)  (2)

y ₁ =r cos (θ+α)  (3)

tan α=x ₀ /y ₀  (b 4)

r={square root}{square root over ( )}(x ₀ ² +y ₀ ²)  (5)

[0119] On this occasion,

[0120] δ: clearance with sheave [mm]

[0121] R₀: radius position of rotational center of pi n[mm]

[0122] A₀: (x₀, y₀): x, y coordinates of point A₀ [mm]

[0123] A₁: (x₁, y₁): x, y coordinates of point A₁ [mm]

[0124] θ: rotational angle of pin [° ] (left rotation positive)

[0125] α: angle of point A₀ [° ]

[0126] r: distance from rotational center of pin to point A₀ [mm]

[0127] β: sheave one side angle [° ]

[0128] c: amendment value of pin end face shape [mm]

[0129] ±^(*1): (+) when x₀ is positive, (−) when x is negative

[0130] ±^(*2):(+) when y₀ is positive, (−) when y₀ is negative

[0131] ±^(*3):(+) when x₀ is negative, (−) when x₀ is positive

[0132] When referring to the amendment value c of the shape of the end face of the pin, c=0 when the end face of the pin 26 c is flat face. When the shape of the end face of the pin is an arc, the amendment value c is analyzed as follows.

[0133] When the pin end face 26 c is the R shape on X axis, that is, when the radius direction of the pulley (in the up and down direction of the pin in FIG. 11; on Y-axis) is cylindrical shape having the same dimension, the amendment value c of the shape of the pin end face is as follows, with referring to FIG. 12.

c=2{Rp−{square root}{square root over ( )}{R p ²−(−x ₀ +a)²}}  (6)

[0134] On this occasion,

[0135] P p: pin end face R [mm]

[0136] a: discrepancy of R center with respect to the rotational center of the pin[mm]

[0137] For instance, when R p=10, a=0.011, c=2 {10−{square root}{square root over ( )}{100−(−x ₀+0.011)²}}

[0138] On the other hand, when the shape of the pin end face is the R shape on Y axis, that is, when the longitudinal direction of the belt (in the front and rear direction of the pin end face in FIG. 11; on X axis) is cylindrical shape having the same dimension, the amendment value c of the shape of the pin end face is as follows, with referring to FIG. 13.

c=2{Rp−{square root}{square root over ( )}{Rp ²−(y ₀ −b)²}}  (7)

[0139] On this occasion,

[0140] b: discrepancy of R center with respect to the rotational center O of pin[mm]

[0141] For instance, when Rp=10, b=0, c=2 {10−{square root}{square root over ( )}(100−y ₀ ²)}

[0142] Furthermore, when the R shape of the pin end face is inclined on X and Y coordinates, the amendment value c of the shape of the pin end face is as follows, with referring to FIG. 14.

c=2{Rp−{square root}{square root over ( )}{Rp ²−(−x ₀ +a)² }−y ₀(tan φ−tan β)αx ₀tan κ}  (8)

[0143] On this occasion,

[0144] φ: inclined angle on Y coordinates[° ]

[0145] κ:inclined angle on X coordinates [° ]

[0146] For instance, when R p=10, a=0.011, c=2 {10−{square root}{square root over ( )}{100−(−x ₀+0.011)² }−y ₀(tan φ−tan 11°)+x ₀ tan κ}

[0147] Next, the clearance δ in the respective points of X and Y coordinates is shown in detail in FIG. 15 through FIG. 26 with the pin rotational angle θ as a parameter on the basis of the above-mentioned equations.

[0148]FIG. 15 through FIG. 18 show the relation between the pin which end face shape is flat face (c=o) and the clearance δ (both sides). In the concrete, FIGs. 15 and 16 show x₀=0, that is, the clearance δ in each point of Y coordinates on the line Y for the center of the pulley. FIG. 15 shows the case where the effective diameter of the pulley (the radios position R₀ of the pin rotational center O) is small diameter, and is on the minimum diameter position on design, for instance, and FIG. 16 shows the case where the effective diameter of the pulley is big diameter, and is on the maximum diameter position on design, for instance.

[0149]FIG. 17 and FIG. 18 show y₀=0, that is, the clearance δ in each point of X coordinates in the center of radius direction of the pin (on X axis). FIG. 17 shows the case where the effective diameter of the pulley (the radius position R₀ of the pin rotational center) is small diameter, and is on the minimum diameter position on design, for instance, and FIG. 16 show the case where the effective diameter of the pulley is big diameter, and is on the maximum diameter position on design, for instance.

[0150] In FIG. 15 through FIG. 19, the clearance δ on the X coordinates is 0.02-0.06 [mm] although the clearance δ on the Y coordinates is 0.001-0.005 [mm]. As known from this, the clearance δ in each point on X coordinates as shown in FIG. 17 and FIG. 18 is more than one figure in comparison with the clearance δ in each point on Y coordinates as shown in FIG. 15 and FIG. 16. When the effective diameter of the pulley is big or small, it is the same story.

[0151] That is, concerning the sensitivity of the coordinate with respect to the change of the substantial pin width B (the clearance δ of the pin with the sheave), X coordinates is more than ten times in comparison with Y coordinates. The change of the substantial pin width by Y coordinates is small, several micron, and keeps within the bounds having no big influence in fact if it is disregarded, different from the change by X coordinates.

[0152] Then, even if the R shape of the end face 26 c of the pin 26 is set on X coordinates only, that is, even if the end face 26 c is cylindrical shape formed so as to be the same radius in each point on Y axis (arc shape only in the direction along X axis), no big influence is given to the substantial change of the pin width with the pin rotation on practical use.

[0153] When the end face of the pin is made cylindrical and it is precisely formed with a grinding machine, machining of only one direction (two-dimensional machining) is sufficient. So, the machining is made easy in comparison with the spherical shape for which three-dimensional machining is necessary, and highly accurate pin end face shape can be obtained. Furthermore, Hertz stress is made about half in comparison with the spherical shape, and this cylindrical shape is excellent in its strength and durability. That is, in order to let the belt-type continuously variable transmission have a predetermined torque capacity, it is necessary hold a belt by a pulley with predetermined pressing force. For this reason, big pressing force acts on the pin end face from the sheave side. But, the Hertz stress corresponding to the pressing force is widely made small in comparison with the spherical shape by making the pin end face cylindrical, and the strength of the pin corresponding to the above-mentioned predetermined torque capacity can be secured.

[0154] Taking the change of the pin width by Y coordinates into consideration, the pin end face can be made spherical. In this case, the change of the pin width on Y coordinate is smaller than the change on X coordinates and highly accurate machining on a sphere is troublesome, and the Hertz reaction is made high. But, the pin end face having less change of the pin width with the pin rotation can be obtained, and the shape of the pin end face may be spherical by overcoming the above-mentioned defects.

[0155] Next, the results of the concrete example wherein the shape of the pin end face is an arc (R) shape will now be explained according to FIG. 19 through FIG. 26. In these drawings, a cylindrical shape wherein the pin end face in the shape of R having a predetermined radius (for instance, R radius; 10 [mm]) is formed along X axis is used. The change of the clearance δ in each point on X axis is shown with the rotational angle of the pin θ as a parameter.

[0156]FIG. 19 through FIG. 23 show the case where the effective diameter R₀ of the pulley is the minimum diameter. FIG. 19 shows that the discrepancy a of R center with respect to the rotational center O of the pin in X coordinates is 0 (a=0), that is, when the center of R radius of the pin end face is positioned on the normal plane passing through the rotational center O of the pin, y₀=0, that is, shows the value on the center line (X axis) in the radius (up and down) direction of the pin. FIG. 20 shows that the discrepancy a is 0 (a=0), and y₀=1.5, that is, shows the value upper 1.5 [mm] (in the direction of outside diameter of the pulley) from the center line (X axis) in FIG. 11. FIG. 21 shows that the discrepancy a is 0 (a=0), and y₀=−1.5, that is, shows the value lower 1.5 [mm] (in the inside diameter direction of the pulley) from the center line (X axis) in FIG. 11.

[0157]FIG. 22 shows the value of y ₀=0 (on the center line; on X axis) when the center of R radius of the pin end face on X coordinates is shifted 0.1 [mm] in the right direction (in the positive direction) (a=0.1) FIG. 23 shows the value of y₀=0 (on the center line) when a=−0.1, that is, the center of R radius of the pin end face is shifted 0.1 [mm] on X coordinates with respect to the rotational center of the pin in the left direction (in the negative direction).

[0158]FIG. 24 through FIG. 26 show the case where the effective diameter R₀ of the pulley is the maximum diameter. FIG. 24 shows the discrepancy a is 0 (a=0) and shows the value of y₀=0 (center line; on X axis) FIG. 25 shows the discrepancy is 0.1, that is, shows the value of y₀=0 when the center of the R shape of the pin end face is shifted 0.1 [mm] in the right direction (in the positive direction) with respect to the rotational center of the pin on X coordinates. FIG. 26 shows the discrepancy a is −0.1, that is, shows the value of y₀=0 when the center of the R shape of the pin end face is shifted 0.1 [mm] in the left direction (in the negative direction) with respect to the rotational center of the pin on X C,) coordinates.

[0159] As clear from the comparison between FIGs. 19, 20, 21, 24 and with FIGs. 17, 18, concerning each rotational angle θ of the pin, the bigger the X coordinate is in (+) direction and in (−) direction, the bigger the clearance δ is so as to be direct proportion when the pin end face 26 c is flat face. But, when the pin end face is made R shape, the clearance δ is small, several micron, and the change of the clearance δ on each X coordinates has the minimum value. This is the same inclination even at the center position of Y axis (y₀=0; on X axis) (see FIG. 19), and even at the position shifted on the upper or the lower hand from the center position (X axis)(see FIG. 20 and FIG. 21). And, this is the same inclination even if the effective diameter of the pulley is small diameter (see FIG. 19) or big diameter (see FIG. 24).

[0160] The substantial pin width in X coordinates is increased or decreased, that is, about +3 micron is increased in Y₀=1.5 as shown in FIG. 20 (the point of 1.5 [mm] on the upper hand of the pin) and about 3 micron is decreased in y₀ =−1.5 (the point of 1.5 [mm] on the lower hand of the pin) with respect to y₀=0 (the center line) as shown in FIG. 19. This is decreased by the deflection of the pin in Y direction.

[0161] Therefore, the shape of the pin end face 26 c is preferably arc (R) shape on at least X coordinates in comparison with plane shape (the prior art having R shape in Y axis direction is almost similar) since the variation of the clearance δ (substantial pin width) with respect to the rotational angle of the pin is small.

[0162] The influence of the center of the R shape of the pin end face will now be reviewed according to FIG. 22 through FIG. 26. When the center of the R shape is moved with respect to the rotational center O of the pin on X coordinates, the minimum value and its X coordinate value of the clearance between the pin end face and the sheave are changed. If the effective diameter of the pulley into which the belt is wound is changed, this is the same inclination (see FIG. 22 and FIG. 25).

[0163] Subsequently, the variation of the rotational angle of the pin will now be explained on the basis of FIG. 27 and FIG. 28. Since each link 25 is curved by biting the belt into the pulley and the pin 26 is held, being united with the link, the variation η of the rotational angle of the pin is the same as the curved angle η of the link.

[0164] If the radius of the rotational center of the pin (

pitch circle) (the effective diameter of the pulley) from the center of the pulley is R₀, the link pitch is P, the variation η of the rotational angle of the pin is as follows.

η=sin⁻¹ {P/(2R ₀)}

[0165] On this occasion,

[0166] η: variation of rotational angle of pin [° ]

[0167] P: link pitch[mm]

[0168] R₀: radius of rotational center of pin[mm]

[0169]FIG. 28 is a view for showing the variation η of rotational angle in each value of the effective diameter of the pulley (radius R₀) with the link pitch P as a parameter. For instance, in case of the link pitch 8 [mm] of the belt, the value of the variation η of the rotational angle corresponding to the minimum value a of the effective diameter of the pulley (radius R₀) is η a, and the value of the variation η of the rotational angle corresponding to the maximum value b of the effective diameter of the pulley is η b.

[0170] Subsequently, the optimum ratio of the center position on X coordinates in the R shape of the pin end face will now be explained according to FIG. 29 through FIG. 31.

[0171]FIG. 29 is a view for showing the change of the clearance δ between the pin end face and the sheave on X coordinates with the rotational angle θ of the pin as a parameter in such a state that the center of the R shape of the pin end face is shifted predetermined quantity (that is, the discrepancy a is changed) in X direction with respect to the rotational center O of the pin. In FIG. 29, where the clearance δ becomes to be the minimum is contact point P (P₁, P₂, P₃) between the pin end face and the sheave, and the change of the contact point P is the variation μ of the pin width B (the longitudinal direction of the pin 26) by the rotation of the pin, and the variation μ can be obtained from the above-mentioned value δ and the value X.

[0172] Improvement of noise when each divided pin is bitten into the sheave is

[0173] 1) to decrease the difference between the values of e and d at the positional angle where the pin is bitten into the sheave and

[0174] 2) to decrease the variation ε of the clearance δ with respect to the change of the pin rotation θ and to decrease the quantity in the direction where the pin width increases with respect to the change of θ as much as possible.

[0175] On this occasion,

[0176] e: value X at positional angle where pin is bitten into sheave [mm]

[0177] d: discrepancy of center of pin thickness with respect to rotational center of pin [mm]

[0178] ε: variation of pin width by pin rotation (both sides) [μ]

[0179]FIG. 30 and FIG. 31 show the variation ε of the pin width in the rotational angle θ of each pin with the discrepancy a of the center of R shape Rp of the pin end face with respect to the rotational center of the pin as a parameter. In the figure, the link (plate) attaching angle f is the angle between Y axis of the respective divided pins 26 a, 26 b and the line orthogonal to the line in the longitudinal direction of the link (the line (Z axis) orthogonal to a straight line (X axis) when the belt is in the state of the straight line) , which is set by the strength of the link or the like. When the belt is wound around the pulley, each link is bent. Since the respective divided pins are held, uniting with the plate, the pins are rotated at the same bent angle. The divided pin 26 b of the front side at the time of moving the belt in a pair of the divided pins is rotated in the left direction (in the positive direction). In general, the divided pin 26 b of the front side at the time of moving the belt in a pair of divided pins is attached so as to incline in advance, rotating a predetermined angle in the left direction (in the positive direction), having consideration for such fact that the contact point of transmitting the load between a pair of divided pins moves in the positive direction of Y axis. On this occasion, the divided pin 26 a of the rear side in the moving direction of the belt is attached such that the link attaching angle is inclined a predetermined angle in the right direction (in the negative direction). So, both divided pins 26 b, 26 a are attached with mirror symmetry so as to sit on the sheet hole 30 a of the link plate 25.

[0180] In FIG. 30, the effective diameter of the pulley is the minimum a, and the variation η a of the rotational angle at the minimum diameter a from the link attaching angle f is the bounds of rotational angle to be used by the pin. On this occasion, in FIG. 30, the R shape radius of the pin end face Rp=10 [mm], and this figure shows the X coordinate at y₀=0. As known from FIG. 30, the discrepancy a of the center of the radius Rp, which is the smallest variation of the pin width in the above-mentioned bounds η a of the rotational angle to be used by the pin is on the position where the variation ε of the pin width which causes the discrepancy a of the center of the radius Rp is equally distributed in its positive (+) rotational direction and in the negative (−) rotational direction (is not always a positive value or a negative value), and is on the line aA between the discrepancy 0 and an. And, the point aA is known from a calculation equation, such as linear supplement or the like or the graph of FIG. 30. On this occasion, the divided pin 26 b rotates to the angle g in the negative direction (in the right direction) from the link attaching angle f being in a straight line state. The variation ε of the pin width is both about 1.7 [μ] in the positive rotational direction and the negative rotational direction.

[0181]FIG. 31 is a view similar to FIG. 30 in case where the effective diameter of the pulley is the maximum diameter b. In case of the maximum diameter b, the variation η of the rotational angle of the pin is η b, the variation η b of the rotational angle from the link attaching angle f of the pin is the bounds of the rotational angle to be used by the pin. The discrepancy aA corresponding to the smallest variation of the pin width is the same variation of the pin width at the link attaching angle f on the positive rotation side of the bounds of the rotational angle to be used, similar to the case of the variation η a in the smallest value a in the effective diameter of the pulley. And, the variation of the pin width in the discrepancy aA on the negative rotation side is almost 0 value. Then, it is confirmed that the above-mentioned optimum discrepancy aA has no problem when the effective diameter of the pulley is the maximum value. On this occasion, in the maximum effective diameter, the divided pin rotates from the link attaching angle f to the angle h which is the positive value.

[0182] Then, the optimum value of the shape of the pin end face is at least arc (R) shape on X coordinates. And, the radius Rp of the R shape is preferably within the bounds of 5-15 [mm] since it is difficult to widely make small in the problem of the strength by Hertz stress or the like. In the embodiment, it is almost 10 [mm]. Then, by making the pin end face the R shape, the clearance δ between the pin end face and the sheave by the rotational angle of the pin, that is, the substantial variation of the pin width abutting on the sheave at the predetermined rotational angle of the pin is restricted within the extremely small bounds. Furthermore, when the R shape of the pin end face and the center of the radius Rp are shifted with respect to the rotational center O of the pin (the discrepancy a), the curve which the variation ε of the pin width in the rotational angle θ of each pin draws has the minimum value on the lower hand (on minus (−) side). Therefore, the center (the discrepancy a) of the arc (R) shape of the pin end face with respect to the rotational center of the pin is determined in such a manner that the variation of the pin width is equally distributed on the positive rotation side and the negative rotation side, especially in the smallest effective diameter of the pulley wherein the bounds of the rotational angle to be used by the pin is wide, so as to make the variation of the pin width minimum within the bounds of the rotational angle to be used by the pin. By doing so, the optimum shape of the pin end face can be obtained.

[0183] As an instance, when the smallest effective diameter a of the pulley (the radius R₀ from the center of the pulley to the center line of the pin y₀=0) is 28.2 [mm] and the maximum effective diameter b of the pulley is 68.8 [mm] , the variation η a of the rotational angle in the smallest effective diameter a is 8.1 [° ], and the variation η b of the rotational angle in the biggest effective diameter b is 3.3 [° ] if the link pitch P is 8 [mm]. If the link attaching angle f of the pin is 5 [° ], the discrepancy aA corresponding to the smallest value of the variation μ of the pin width (about 1.7 [μ]) is 0.03 [mm]. On this occasion, the rotational angle g of the pin on the negative side (after biting into the pulley) in the smallest effective diameter of the pulley is −3.1 [° ], and the rotational angle h of the pin of the negative rotation side (after biting into the pulley) in the maximum effective diameter of the pulley is 1.7 [° ].

[0184] Then, if the above-mentioned discrepancy a is set below 0.2 [mm], the variation of the pin width is restricted to the bounds having no problem on practical use. Since in the divided pin 26 a of the rear side in the moving direction of the link 25, the link attaching angle is minus (−) direction (the right rotation direction with respect to Y axis), the discrepancy a is below −0.2 [mm]. Then, the discrepancy a on X coordinates is within the bounds of +0.2- −0.2 [mm].

[0185] Besides, when the discrepancy of the center (X coordinates) of the radius Rp of the R shape of the pin end face with respect to the rotational center O of the pin is 0, the variation of the pin width within the bounds of the change of the rotational angle of the pin is the maximum in the rotational angle of the pin (the same as the link plate attaching angle of the pin) in the position where the belt starts to bite into the pulley in the divided pin 26 b of the front side in the moving direction of the belt, and is made smaller in the rotational angle of the pin when the belt is rotated so as to finish the rotation of the pin. In the result, the variation of the pin width is made bigger within the bounds of the change of the rotational angle of the pin. But, in case where the above-mentioned discrepancy does not include 0, that is, in case where the rotational center of the pin and the center (X coordinates) of the radius of the R shape of the pin end face are not correspond with each other (the shifted direction is determined by the link plate attaching angle of the pin on the positive side (the right direction) or the negative side (the left direction) with respect to Y axis for the center of the radius of the pulley) , the variation of the pin width can be restricted to the smaller value within the bounds of the change of the rotational angle of the pin. Therefore, the above-mentioned discrepancy does not preferably include 0 (−0.2<ah<0.2, but does not include 0).

[0186] Subsequently, the loss accompanied by the rotation of the pin itself when the pin is bitten into the sheave, so-called spin loss will now be explained according to FIGs. 32 and 33. For the spin loss, it is the best way that the value of the variation of the pin width by the rotation of the pin (both sides) ε[μ] X the X value e [mm] at the positional angle of biting into the sheave of the pin (see FIG. 29) is the smallest. But, to prioritize noise improvement is better when it is difficult to reconcile improvement of spin lose and improvement of noise.

[0187]FIG. 32 and FIG. 33 are views for showing the biting position on X coordinates in each rotational angle of the pin θ [° ] with the discrepancy a [mm] of the center of the R shape of the pin end face as a parameter. FIG. 32 shows the case where the effective diameter of the pulley is the minimum diameter a, and FIG. 31 shows the case where the effective diameter of the pulley is the maximum diameter b. In both figures, the radius Rp of the R shape of the end face of the pin is 10 [mm] , and both figures are obtained from the X coordinates at y₀=0.

[0188] In FIG. 32 where the effective diameter of the pulley (the radius R₀ of the pulley to the rotational center of the pin) is the minimum diameter a, the biting position e of the pin is about −0.13 [mm] in the positive (+) rotation side (the link attaching angle f) of the rotational angle θ of the pin, and is about 0.12 [mm] in the negative (−) rotation side (g; the negative value) when the discrepancy is aA in the variation η a of the rotational angle of the pin (see FIG. 28) within the bounds to be used on the basis of the link attaching angle f of the pin. In FIG. 33 where the effective diameter R₀ of the pulley is the maximum diameter b, the biting position e of the pin is about −0.13 [mm] in the positive (+) rotation side (the link attaching angle f) of the rotational angle θ of the pin, and is about −0.03 [mm] in the negative (−) rotation side (g; the positive value) when the discrepancy is aA in the variation η b of the rotational angle of the pin within the bounds to be used on the basis of the link attaching angle f of the pin.

[0189] Therefore, the spin loss value (ε X e) is from ε X (0.012) to ε X (−0.13) when the effective diameter of the pulley is the minimum a, and is from ε X (−0.03) to ε X (−0.13) when the effective diameter of the pulley is the maximum. To be concrete, the link attaching angle f=5[° ], the discrepancy aA of the center of the radius Rp of the R shape of the pin end face=0.03 [mm] , the minimum effective diameter a of the pulley=28.2 [mm], the variations η of the rotational angle to be used at the minimum effective diameter=8.1 [° ] , the rotational angle g of the pin=−3.1 [° ], the maximum effective diameter b of the pulley=68.8 [mm], the variation η b of the rotational angle to be used at the maximum effective diameter=3.3 [° ], and the rotational angle h of the pin=1.7 [° ]

[0190] The spin loss value on the basis of the pin biting position e is within the bounds satisfactory on design. Then, from the view of the improvement of the spin loss, the above-mentioned shape of the pin end face (Rp=10 [mm], its discrepancy a=0.03 [mm]) is optimum shape, and the radius Rp of the R shape of the pin end face =5-15 [mm], the discrepancy a<|10.21| [mm] (but, does not include 0) is proper shape capable of permitting on design.

[0191] Next, the operations of the endless belt for power transmitting 21 will now be explained. As shown in FIG. 3, when the endless belt 21 is bitten into the pulley, a pair of the divided pins 26 a, 26 b are relatively moved, contacting their rolling surfaces 31 a with each other, each rank G . . . of the link chain 32 is bent, each block 22, 23 oscillates with respect to the pin, and the first and the second blocks 22, 23 are relatively moved so as to match with the sheave side, contacting the projecting portions 41 with each other. By doing so, the respective divided pins 26 a, 26 b and the respective blocks 22, 23 are bent along the effective diameter of the pulley unit, that is, along the pitch line (circle) P-P. On this occasion, each block does not always face the central axial line of the pulley.

[0192] But, the outer side face of each block contacts with the sheave side on only projecting outer side face 45 near the pitch circle, and the respective divided pins 26 a, 26 b, arranged corresponding to these outer side faces 45, are contacted with the sheave side. Then, at the time of biting, the projecting outer side face 45 of the second block 22, one divided pin 26 b, the other divided pin 26 a, and the projecting outer side face 45 of the first block 23 are contacted with the sheave side in order in one pitch (1 rank G . . . ) of each link chain 32. Therefore, even if the respective blocks 22, 23 are inclined (to the Y-axis, the X-axis and the Z-axis), gearing into the pulley starts, always dispersing into four parts with respect to one link chain pitch. Then, gearing pitch is made smaller, polygon effects are made decreased. And, the sound at the time of gearing into the pulley becomes to be high frequency, and sound energy is decreased so as to decrease undesired noise.

[0193] Furthermore, the block may be inclined in the front and rear direction (in the longitudinal direction of the belt; with respect to the Y-axis). In the case of the conventional blocks 2, 3 as shown in FIG. 1, the block width W2 with respect to the pulley is the front face width W3 of the block 2, 3 in the right and left direction of FIG. 1 (b) in such a state that the blocks 2, 3 are not inclined, as shown in FIG. 10(a). But, by inclining the block, the amount A projected the thickness of the contacting portion of the block in the longitudinal direction of the belt which is the right and left direction in the figure is added to the front face width W3.

[0194] Since the outer side faces 2 c, 3 c of the conventional respective blocks are inclined faces matching with the sheave side for all faces in the up and down direction (in the radius direction), the contacting portion with the pulley extends all faces of the outer side faces 2 c, 3 c in the shape of crank, as shown in (b) of FIG. 9 (B) . Then, the width t of the contacting portion with the pulley is the maximum dimension t in the right and left direction in the figure which is the longitudinal direction of the belt. The influence by the inclination of the block is received by the thickness t. The block width W2 is increased the amount A (when the thickness of the block is t, and the inclined angle is a, α, A=t·cos α) in comparison with the block having no inclination.

[0195] On the contrary, as shown in FIG. 7 and FIG. 10 (b), in the blocks 22, 23 according to the present invention, the part contacting with the sheave side is only the projecting outer side face 45 having the predetermined bounds near the pitch line. Therefore, the inclination of the block in the front and rear direction influences only the thickness T of the projection portion 41 on which the projecting outer side face 45 positions, as shown in (b) of FIG. 9 (B). Then, since it is not necessary to consider the thickness of the crank part in the up and down portion in the figure, the thickness T of the contacting portion with the pulley is widely made small in comparison with the conventional block. Therefore, in comparison with the block having no inclination, the block width is changed C. But, the variation C is widely small (C<A) in comparison with the conventional one since the thickness of the contacting portion with the pulley is small.

[0196] When the conventional blocks 2, 3 are inclined in the front and rear direction (with respect to the Y axis) , the increasing quantity A of the block width W2 is big, and the load on the sheave is big, so this widely influences the durability of the pulley and the block. But, in case of the blocks 22, 23 according to the present invention, the increasing quantity C of the block width is small, the load on the sheave is small, so the influence on the durability of the pulley and the block is small.

[0197] When the pins 26 a, 26 b are bitten into the pulley, the respective divided pins 26 a, 26 b roll at the rolling surfaces 31 with each other, and the leading pin 26 b is bitten into the inside in the radius direction of the pulley. In this state, the relative clearance between the pin outer side face 6 c and the sheave side is changed and the biting start position of the pin is shifted if both outer side end faces 6 c are a plane in the front and rear direction (in the longitudinal direction of the belt) as the conventional pin 6. That is, the leading side of the pin outer side face 6 c in the belt running direction is firstly contacted with the sheave side, and then, the biting pitch is made bigger. On the contrary, the outer side face 26 c of the pin 26 according to the present invention is curved R in the front and rear direction (in the longitudinal direction of the belt). So, even if the pin 26 b on the leading side is relatively rotated so as to bite into the inside in the radius direction of the pulley, the outer side face 26 c always starts to contact with the sheave side near the apical portion s of the curved face R in the shape of R, and the biting pitch is not made big.

[0198] Furthermore, when the belt 21 bites into the pulley, the abutting position between the opposed face 31 b of the pins 26 a, 26 b and the concave slot 40 of the blocks 22, 23 is slightly shifted from the upper of the pitch circle P-P in the outside diameter direction, as shown in FIG. 3. Then, by abutting the projecting outer side face 45 of each block 22, 23 on the sheave side, the force in the direction as shown by the arrow p acts on the position shifted from the central position of the whole block (in the front and rear direction), and moment acts on the block. But, the moment acting on the block is denied by receiving the force in the direction as shown by the arrow E from the abutting position of the pins 26 a, 26 b so as to decrease the inclination of the block in the radius direction.

[0199] And, when the pins 26 a, 26 b are bitten into the pulley, the respective divided pins 26 a, 26 b both roll on their rolling surfaces with each other as described. The preceding pin 26 b bites into the inside of the radius direction of the pulley. In this state, the relative clearance between the outer side face 6 c of the pin and the side of the sheave is changed and the starting position of biting of the pin is shifted if both outer end faces 6 c are planes in the front and rear direction (the longitudinal direction of the belt) as the conventional pin 6. That is, as shown in FIG. 15 through FIG. 18, the substantial width (the relative clearance between the pin end face and the sheave) of the pin is widely changed by the spin of the pin when the endless belt is bitten into the pulley if the shape of the end face of the pin is plane face (flat face) (one having flat face in X direction if there is the R shape in radius direction (Y direction) is similar, and this is also included) and the contact position between the pin and the sheave (in circumference direction; X direction, radius direction; Y direction) is changed. Then, the polygon effects are made bigger and the slip between the pin and the sheave, especially the slip in the radius direction is made bigger. So, the relative width between the projecting outer side face 45 of the respective blocks 22, 23 contacting with the sheave and the pin is changed and the polygon effects are made bigger so as to cause noise. At the same time, the load on the sheave, the block and the pin is made bigger so as to give bad influence on the durability of a belt-type continuously variable transmission.

[0200] On the contrary, the shape of the end face of the pin according to the present invention is R shape in at least X direction, and the center of the radius Rp of the R shape is shifted the predetermined quantity aA with respect to the rotational center of the pin, and has the shape wherein the variation of the pin width with respect to the rotation of the pin is small. When the pin is bitten into the pulley, the pin rotates. The variation of the pin width by this rotation is small, and the biting pitch of the pin end face into the sheave is maintained constant, the polygon effects is maintained small, and occurrence of noise is decreased. At the same time, the influence on the sheave by the rotational angle of the pin, and the influence on the block is decreased so as to improve the durability of the belt-type continuously variable transmission. Besides, the spin loss of the pin is decreased so as to improve the power transmitting efficiency.

[0201] The above-mentioned embodiment relates to the case where the projecting outer side faces 45 of the two blocks 22, 23 and divided pins 26 a, 26 b start to contact with the sheave side at equal intervals in one pitch. But, in fact, the sound at the time of biting becomes to be white noise by changing frequency since the contacting position is slightly shifted by the curved face R of the pin outer side face 26 c or the like. Then, silence improves. Furthermore, the projecting outer side faces 45 of the blocks 22, 23 and divided pins 26 a, 26 b may be actively designed so as to start to contact at unequal intervals and the frequency may be changed so as improve white noise and to improve silence.

[0202] The present embodiment relates to the endless belt wherein the first and the second blocks 22, 23 are held between the pins 26. But, the shape of the pin end face according to the present invention is not just the thing. For instance, the present invention can be applied to Luk-type endless belt wherein only pin contacts with the sheave, and furthermore, can be applied to all the endless belt wherein the pin contacts with the side of the sheave in a similar way. Besides, the pin is preferably the divided pin. But, this is not just the thing. The present invention can be also applied to one pin having the rolling surface with the link (plate) as shown in the Japanese patent publication gazette No.Tokukosho 58-49746, for instance. In short, the present invention can be applied to the endless belt having the pin having rolling surface so as to rotate with the bend of the link.

[0203] The embodiments which are described in the present specification are illustrative and not limiting. The scope of the invention is designated by the accompanying claims and is not restricted by the descriptions of the specific embodiments. Accordingly, all the transformations and changes belonging to the claims are included in the scope of the present invention. 

1. Endless belt for power transmitting having many pins comprising a pair of divided pins having rolling surfaces capable of abutting on each other, many link plates comprising link chains alternately connected by said pins, and first and second blocks having projection portions capable of contacting with each other in front and rear direction, a concave slot provided on the opposite side for receiving said divided pin, and an open hole penetrating said link chain in said front and rear direction, comprising: said divided pins having shape and length such that both outer side ends in its right and left can be contacted with sheave sides of a pulley; and said first and second blocks having projecting outer side faces at positions almost corresponding to said outer side end faces of said divided pins in both outer side faces of their right and left, projecting in the right and left direction and having a shape capable of contacting with said sheave sides of said pulley, and said endless belt for power transmitting having such a structure that total four parts, a pair of said divided pins, said projecting outer side faces of said first and second blocks, are contacted with said sheave side in order in one pitch of said link chain.
 2. The endless belt for power transmitting as set forth in claim 1 , wherein said projecting outer side faces in said first and second blocks are formed in the shape of almost straight line, having a predetermined inclined angle so as match with the sheave side, and are near pitch line, and are shorter than length in up and down direction of said concave slot.
 3. The endless belt for power transmitting as set forth in claim 1 , wherein said first and second blocks have said concave slots holding and contacting with said divided pins on both side portions of their right and left, and said open hole is formed between said both side portions.
 4. The endless belt for power transmitting as set forth in claim 1 , wherein said divided pin is located in said slot in order to operate such that moment with contact between said concave slot and said divided pin denies moment acting on said first and second blocks since these blocks contact with said sheave side at said projecting outer side face positioning on said projection portion.
 5. The endless belt for power transmitting as set forth in claim 4 , wherein abutting position between said divided pin and said concave slot is located at a position shifted in outside diameter direction with respect to pitch circle of said belt.
 6. The endless belt for power transmitting as set forth in claim 1 , wherein said outer side end face of said divided pin is formed, curved in the longitudinal direction of said belt.
 7. The endless belt for power transmitting as set forth in claim 3 wherein only one of said open hole is formed between said concave slots.
 8. The endless belt for power transmitting as set forth in claim 7 , wherein a guide face is respectively formed on said open hole side of said concave slots, and said guide face and said link plate on utmost outer side of said link chain are abutted on each other.
 9. The endless belt for power transmitting as set forth in claim 1 , wherein a stopper for restricting relative rotation quantity of said divided pin is provided with upper and lower of said concave slot.
 10. The endless belt for power transmitting as set forth in claim 1 , wherein said outer side end face of said divided pin is formed in the shape of a straight line having a predetermined inclined angle, seen from said longitudinal direction of said belt.
 11. Endless belt for power transmitting having many pins each having a rolling surface and many link plates alternately connected by said pins so as to comprise a link chain, comprising: said pin having shape and length wherein its both right and left outer side faces can contact with sides of sheaves of a pulley; and said end face of said pin having curved shape in at least X direction with a longitudinal direction of said endless belt as said X direction.
 12. The endless belt for power transmitting as set forth in claim 11 , wherein said shape of said end face of said pin is almost cylindrical one having curved shape in said X direction.
 13. The endless belt for power transmitting as set forth in claim 11 , wherein said pin is comprised of a pair of divided pins having rolling surfaces capable of abutting on each other.
 14. The endless belt for power transmitting as set forth in claim 11 , wherein said curved shape is R shape which radius is in the bounds of 5-15 [mm].
 15. The endless belt for power transmitting as set forth in claim 14 , wherein the shape of said end face of said divided pin has discrepancy of the center of radius of said R shape with respect to the rotational center of said pin in said X direction, obtained in such a manner that variation of pin width obtained from a clearance between said pin end face and said sheave in said X direction is equally distributed to positive rotational side and negative rotational side of rotational angle in variation of the rotational angle within the bounds to be used by said pin.
 16. The endless belt for power transmitting as set forth in claim 15 , wherein said discrepancy is within the bounds from −0.2 to +0.2 [mm].
 17. The endless belt for power transmitting as set forth in claim 16 , wherein said discrepancy is a value which does not include
 0. 18. The endless belt for power transmitting as set forth in claim 15 , wherein said a pair of divided pins are attached to said link plate so as to sit on a sheet hole formed on said link plate on the side opposite to said rolling surface, and said divided pin of front side of moving direction of said endless belt in a pair of divided pins is attached to said link plate with a predetermined value of positive rotational direction with respect to Y direction orthogonal to said X direction with the rotation in the moving direction of said endless belt as its positive rotation.
 19. The endless belt for power transmitting as set forth in claim 18 , wherein the center of radius of said R shape of said divided pin of said front side has a predetermined discrepancy on rear side of said moving direction of said endless belt with respect to said rotational center of said pin.
 20. The endless belt for power transmitting as set forth in claim 19 , wherein said radius of said R shape is almost 10 [mm] , and said predetermined discrepancy is almost 0.03 [mm].
 21. The endless belt for power transmitting as set forth in claim 13 , wherein at least one block having an open hole being penetrated by said link chain in said X direction, held between said pins adjacent to each other in said X direction, is provided, said block projects in right and left direction at a position almost corresponding to said outer end face of said pin in both right and left outer side faces, and has projecting outer side faces comprised of the shape capable of contacting with said sheave sides of said pulley.
 22. The endless belt for power transmitting as set forth in claim 21 , wherein said block is comprised of first and second blocks, having a projection portion capable of contacting with each other in said X direction and a concave slot for receiving said divided pin on the opposite side, and total four parts, said outer end faces of a pair of said divided pins, said projecting outer side faces of said first and second blocks, are contacted with said sheave side in order in one pitch of said link chain. 